Women make up roughly half of the U.S. workforce but only about one-third of graduate business students. The nonprofit Forté Foundation would like to change that.

NEW YORK (Fortune) -- It's a bit puzzling: Over the past 20 years, as women have made tremendous gains in the business world, the percentage of B-school students who are female has
remained at about 30%, or roughly the same now as in the late '80s. (By contrast, female enrollment in law and medical schools has risen over the same time period to about 50%.)

The Forté Foundation started in 2001 with a mission: to encourage more women to consider getting an MBA, and to provide them with information about how to do it.

Sponsored by 21 companies, among them IBM (IBM, Fortune 500), Goldman Sachs (GS, Fortune 500), Ernst & Young, American Express (AXP, Fortune 500), and Avon (AVP, Fortune 500), and 37 B-schools -- including Harvard, Chicago, Wharton, MIT, and
Columbia -- Forté is holding a series of conferences called "The MBA Value Proposition" in five cities (San Francisco, Los Angeles, Chicago, New York, and Boston) between now and
October 1.

The events are designed to answer questions women may have about everything from how to finance a graduate business degree to what to do if their math skills are rusty. For more
information or to register online, go to www.fortefoundation.org/forum.

I recently spoke with Elissa Ellis Sangster, Forté's executive director, about their work. Some excerpts from our conversation:

Let me play devil's advocate here for a minute and ask, why do women need to go to B-school? Or I'll put it this way: Does anyone really need to get an MBA in order to get ahead in
businesses other than investment banking or consulting?

Well, plenty of people are successful without an MBA. But the degree does give you the ability to take your career to a higher level.

For one thing, it gives you a great network of people who are in a position to support your career in the future, and it teaches you analytical and decision-making skills that are useful
in any industry, so that you have the flexibility and the nimbleness to move easily from one role to another or one industry to another.

That's an important asset, especially in this economy. An MBA is really an investment for life.

Beyond that, the Bureau of Labor Statistics has done studies showing that the more education you have, the more you earn over the course of your lifetime, and the less likely you are to
be unemployed.

Right now, the overall unemployment rate is almost 10%, but for people with a master's degree, it's 2.4%. That's pretty striking.

Why are there still relatively few women MBAs?

Well, the thing that launched Forté eight years ago was a huge study of this question, by researchers at the University of Michigan and Catalyst that revealed four main reasons.

First, women were concerned about balancing work, school, and home-life responsibilities if they went back to school.

Second, they didn't see many role models -- female MBAs who were managing to juggle everything.

Third, they expressed doubts as to whether they had the quantitative background and the advanced math skills to handle MBA courses.

And fourth, they weren't getting much, if any, encouragement from their employers to get an advanced degree.

To a large extent those concerns have not gone away. So we address those issues in our forums and through our online network of about 40,000 businesswomen. We're also reaching out to
undergraduate students in fields like liberal arts and engineering, holding on-campus events called "Career Labs" that encourage them to consider business careers.

How do you view women's role in the business world today in general? Is the glass half empty or half full?

But it's half empty at the very top. There are still only 13 female CEOs of major companies, up from four a few years ago. I did the math, and at that rate of advancement, it will take
women until 2096 to reach parity with men.

Also, Catalyst did a study showing that, at the senior management level -- one or two rungs below CEO -- 19% of women lost their jobs in this recession, versus 6% of men. I don't know
why. It's probably due to a combination of things, including the fact that women often don't have the kinds of strong professional networks their male counterparts have. An MBA could help
with that!

Talkback: Have you considered getting an MBA? Why or why not? If you have one, has it given your career a significant boost? Sign on to Facebook below and tell us.